Scanning device for television



Aug. 19,1930. H. w. BALLARD T AL SCANNING DEVICE FOR TELEVISION FiledAug. 15, 1928 Harry W. Ballard Jack F Baflard iNVENTORS BY M m wz sPatented- PATENT OFFICE UNITED sures nan! W. BALLAD!) AND JACK I.BALLABD, DETROIT, MICHIGAN SCANNING DEVICE FOR TELEVISION Applicationfiled August 1a, 1928. serial no. 299,232.

This invention relates ,to television and particularly to devices forscanning pictures,

lms and mirrors or the like, such as are used in television apparatus.An object of the invention is to provide a scanning device fortelevision purposes, more com act than present constructions and betteresi ned to withstand the necessary high speed 0 the rotative member.

More specifically the object is to mount a stationary light bulb withina rotative cylindrical shell and form said shell with a substantiallyhelical series of apertures through which may be emitted beams of lightwhich, upon rotation of the shell, will successively traverse thesurface to be scanned, so as to jointly cover substantially its entirearea durin each revolution of said shell.

llhese and various other objects the invention attains by theconstruction hereinafter described and illustrated in theaccompanyingflrawing, wherein: ig. 1 is a view in front elevation of theimproved scanning device and its drive motor. I

Fig. 2 is a vertical sectional view of the same taken upon the line 22of Fig. 1.

In these views the reference character 1 designates a base formedpreferably of suitable insulating material such as hard rubber, bakeliteor the like. Said base rigidly carries a suitable upstanding socket 2 toreceive the shank 3 of a suitable electric bulb 4. The illustrated bulband socket are of a radio type, primarily designed toreceive televisionbroadcasting, the shank 3 being provided with contact stems 4 (usuallyfour in number) to engage contacts 5 carried by the base within thesocket 2, having the usual connection to binding posts 6.

Rigidl embracing the socket 2 and projecting t ereabove is a sleeve 7 onwhich is journaled a sleeve 8 having a central pulleyforming portion 9engageable by a drive belt 10. The latter in the illustrated embodimentof the device enga es a driving pulley 11 fast upon the shaft 0 avertically mounted motor 12. 7

At its upper end the sleeve 8 is enlarged to form a circular head 13above which engages an annular flange 14 upon the sleeve 7 to maintainthe proper engagement of the rotatmg and stationary sleeves. To the head13 is rigidly secured the lower end of a cylindrical sheet metal shell15, coaxial with and substantially enclosing the bulb 4.

Exterlorly adjacent to said shell is vertically mounted an opaque plate16 formed preferably of sheet metal and formed with a central window 17,preferably rectangular and having its central .axis radial to the bulb4. Said member is supported as described in any suitable manner as forexample, by rigidly engaging the lower portion of sald member by a pairof spaced vertical rods 18, horizontally bent at their lower ends andsuitably secured to-the lower portion of the sleeve 7 The bulb 4 ispreferably of a neon gas type and is silvered or otherwise provided witha reflecting surface, except upon its ortion 19 which faces toward thewindow 1 The rotating shell 15 is formed with a substantially helicalseries of apertures 20, for discharging beams of light from the bulb 475 through the shell 15, the arrangement being such that when the shell15 is rotated the beams radiated through said apertures will traversethe window 17 at slightly varying levels and will traverse substantiallythe entire area of said window during each complete revolution of theshell. Thus a picture, mirror, film or other suitable surface (notshown), mounted for illumination by said beams, will be scanned ortraversed thereby through substantially its entire area.

From the foregoing description it is believed that the utility of thedescribed device, particularly in connection with television receivingapparatus, will be clearly evident. The control of the light by acylindrical shell of the described and illustrated character is muchpreferable to use of an apertured disc for such purpose since such ashell may be made more compact'than a disc serving a similar purpose andis much better able to withstand the necessary high velocity torque andresulting centrifugal strains. Furthermore, the fact that the describedshell can be given a considerably lesser diameter change within thespirit and scope of the subthan a disc serving the same purposematejournaling said drum upon said socket to rorially reduces suchcentrifugal strains as comtate about the socket axis, and means forpared to those arising in a scanning disc. actuating the drum in suchrotation.

Furthermore, a scannin shell such as this In testimony whereof we signthis speciinvention employs is partlcularl ada ted to fication.

be compactly associated with t e bub and HARRY W. BALLARD. '70 socketwhich are an essential of such an appa- JACK F. BALLARD. ratus.

While it will be apparent that the illus- 1o trated embodiment of ourinvention here dis- 7 75 closed is well calculated to adequately fulfillthe objects and advanta es primarily stated, it is to be understood t atthe invention is susceptible to variation, modification and joinedclaims.

What we claim is:

1. In a scanning device for television, the

combination with a light bulb, of asubstan- 2o tially opaque cylindricalshell inclosing said 85 bulb and rotative about the bulb axis and formedwith a substantially helical series of apertures, means for rotatingsaid shell, and an opaque member mounted exteriorly adjacent to saidshell, formed with a window traversed by the rays emitted from said bulbthrough said apertures.

2. In a scanning device for television, the combination with a base anda socket sur- 80 mounting said base, of a light bulbengaging 95 saidsocket, a sleeve secured to and pro ectin above said socket, an outersleeve journale upon the first mentioned sleeve, a substantially opaquecylindrical shell carried by said 85 outer sleeve coaxial with andsubstantially no inclosin said bulb and formed with asubstantialFyhelical series of apertures, means for rotating said outer sleevetogether with the shell carried thereby, a member formed of opaquematerial mounted exteriorly ad- 105 jacent to said shell and formed witha window adapted to be traversed by rays from said bulb, emitted throughthe apertures of said shell as the latter rotates, and means attachingsaid window-forming member to 110 said socket.

3. In a scanning device for television, the combination with a base anda socket surmounting said base, of a light bulb engaging said socket, asleeve secured to and pro ect- 5 ing above said socket, an outer sleevejournaled upon the first mentioned sleeve, a substantially opaquecylindrical shell carried by said outer sleeve coaxial with andsubstantially inclosing said bulb and formed with a 124) substantiallyhelical series of apertures, and means for rotating said outer sleevetogether with the shell carried thereby. 4. In a scanning device fortelevision, the combination with a socket and a lamp in said 126 socket,of a substantially opaque cylindrical shell enclosing said lamp andhaving its axis substantially coincident with the extended axis of saidsocket, and formed with a substantially helical series of apertures,means

